1. Field of the Invention
The present invention relates generally to farm machinery. More particularly the present invention relates to hay and forage equipment and a method and apparatus for decreasing the drying time for hay and other forage crops that are mown.
2. Background Art
In the past, hay and other forage crops were mown in the field and allowed to drop into a swath where they were mown for drying. There is a significant risk in many parts of the country and world that hay will be rained on before it is sufficiently dry to bale using this traditional method. Therefore, in order to speed this process, a variety of equipment has been invented and used comprising two types of operation:                1. conditioning, which is the crimping/crushing of the stems or scuffing of the waxy outer surface to enhance the transport of moisture out of the cells, and        2. tedding, which is a process of fluffing the swath to expose more of it to the air.Usually, the conditioning operation is performed in conjunction with the original mowing process and the tedding operation is a separate operation.        
There are two basic mowing technologies currently in use, including sickle bar mowers and rotary disc mowers. Rotary disc mowers are becoming the preferred technology in many areas, and are typically offered in two configurations: as a mower or as a mower/conditioner. A 3-point mounted disc-type mower/conditioner 100 is shown in FIG. 1. Disc mowers and mower conditioners are also mounted onto wheeled trailers. The 3-point mower/conditioner 100 is mounted to the 3-point hitch 12 of a tractor (not shown) with a frame 115 and is driven via a Power Take Off (PTO) shaft 120. It is comprised of two basic components, a cutter bar 102 and a conditioning/crushing device 130.
The Cutter bar 102 is comprised of a number of discs 110 powered from the PTO shaft 120 through the V-Belt drive 122 to a gear drive arrangement that powers the disc drive shafts 200 shown in FIG. 2 illustrating a single disc 110. Each disc is rotatably mounted in the cutter bar 102, wherein they rotate about a shaft 200. Disc drive shafts are typically driven by a gear train comprising a series of spur gears, or a gear train comprising one common main shaft with a bevel gear drive for each disc drive shaft. The thickness of this drive train is kept at a minimum to minimize the affect on flow of material over the cutter bar as it is being cut. Two knives 105 are pivotally attached to each disc 110 with fasteners 210. An extension 220 can be fastened to and extend above each disc 110. The extension may be a truncated cone shape, a right circular cylinder shape, or another right cylindrical shape. The knives 105 sweep out a mowing area 242 that is defined by a pair of concentric circles defined by the innermost and outermost cutting edges. These concentric circles have radii, rmin 230 and rmax 240, respectively.
The illustrated mower/conditioner 100 has a conditioning/crushing device 130 for conditioning the forage after it has been cut by the cutter bar 102, to accelerate drying. A crushing device 130 may comprise a pair of crimping rollers, or a flail-type roller. The power required to rotate such a crushing device 130 is transferred with an intermediate shaft 125.
A disc mower is similar, with the exception that it does not include a crushing device. FIG. 1a illustrates the cutter bar 102 of a disc mower in operation as it is being towed through a field by a tractor 10. This cutter bar is comprised of four pairs of counter-rotating discs 110. The discs are forced to counter-rotate and remain in-time with the other discs, by the gear drive connecting the drive shafts 200 (FIG. 2). The timing control of the discs is critical to provide overlap of the mowing areas 242 which is necessary to provide adequate mowing. The cutter bar 102 illustrated in FIG. 1a further comprises one extension 220, mounted to the disc farthest from the tractor 10.
Extension 220 is included to assist in moving the cut crop. The standing crop is illustrated 20, as well as the cut material 22. The discs 110, without extensions, allow the crop to flow directly over the top and the resulting swath of cut material 22 is as wide as the width of standing material being cut. However, the disc 110 with extension 220 moves material to the side, resulting in a narrowing of the swath of cut material 22. This narrowing provides for an area 24 where there is no cut material 22. This provides a separation between the cut crop 22 and the standing crop 20 so that the cut crop 22 does not intermingle with the standing crop 20, which could cause difficulties when cutting the standing crop 20. It further provides an area for the tractor tire to run without driving on cut crop 22.
In a mower conditioner, extensions 220 are often used to narrow the swath so that the conditioning element, similar to crushing device 130, can be narrower than the cutter bar.
FIG. 1b further illustrates the flow of the crop as it is cut. The standing crop 20 is impacted by a knife 105 when its stem falls within the mowing area 242 of a disc 110. Upon impact, the stem is cut and the crop tends to be propelled rearward, with the cut edge leading (rearward). It is further lifted, due to the geometry of the disc, such that it will become airborne before falling back to the ground. A cover 124 is provided over the top of the cutter bar to control the cut crop. The cut material 22 is then deposited onto the ground, lined-up consistently, as illustrated.
The tedding process is performed to fluff-up the swath of cut material, at least partially by disrupting this consistent orientation, and is typically performed as a separate operation. The drawbacks of this approach are several and comprise:                1. multiple passes over the field means more compaction of the soil and more damage to the plant life;        2. multiple passes also increases the machinery operator's time in the field and fuel usage; and        3. handling the hay and operating on it results in leaf loss, and consequent loss of feed value—especially when the hay has dried down significantly before the additional operation.        
There is, therefore, a need for a method and device for mowing, conditioning, and tedding in a single pass. There is also need for the machinery carrying out these simultaneous operations to be rugged, simple, inexpensive, and light.